1. Technical Field
The present disclosure relates to a brake lining and a brake lining retention device of a disc brake of a motor vehicle.
2. Description of Related Art
In the field of wheel brakes, the subject of undesirable noise production assumes great significance. In addition to friction-induced vibrations, such as, for example, squealing, however, there are also produced other noises which can be attributed to occurrences of roadway unevenness or brake actuation operations.
For example, floating calliper brakes are used in the utility vehicle sector. In this instance, in order to support the high braking torques which occur, the brake linings are supported by so-called lining horn-like members in an axially fixed brake carrier in both rotation directions of the brake disc. The floatingly supported brake calliper then produces only the brake application force with which the brake linings are pressed against the brake disc. So that the brake linings can be moved in a free-running manner in the lining shaft, the brake linings and brake lining shaft are processed with a specific tolerance position relative to each other. In this case, the lining horn-like members of the brake carrier are produced parallel with each other in the normal state. Occurrences of play of different magnitudes can thereby be produced. During manual assembly of the brake carrier (for example, after changing brake discs), however, it is possible for the lining shaft shape of the brake carrier to become deformed by the screw tightening torque in such a manner that the play at the tip of the lining horn-like members becomes further increased. During vehicle operation, the brake lining abuts, as a result of gravitational force in accordance with the installation position of the brake calliper, the lining horn-like member which leads with respect to the brake disc (so-called “9 o'clock installation position”), the lining horn-like member which trails with respect to the brake disc (so-called “3 o-clock installation position”) or in an undefined manner (so-called “12 o-clock installation position”).
However, a brake torque can be supported only when the brake lining abuts the lining horn-like member which trails with respect to the brake disc. Should the brake lining abut the horn-like member which leads with respect to the brake disc as a result of gravitational force, it must first overcome the entire play which has been formed by the production tolerances and brake carrier deformation. During this time, however, the brake lining picks up speed as a result of the brake disc rotation before it strikes the lining horn-like member at the trailing side and brake torque can be transmitted. Therefore, this results in a delayed response of the brake and an undesirable noise formation. When the brake is released, the brake lining then falls back onto the lining horn-like member at the leading side, which again results in an impact noise.
FIG. 4 is a lateral top cross-sectional view of a brake lining which is retained in a brake carrier 2 according to the prior art, of which only the brake lining carrier plate (also referred to as the lining carrier plate below for brevity) 41 can be seen in the sectional view of FIG. 4. In this known brake lining retention device 40, the brake carrier 2 is constructed with respective lining horn-like members 3, 4 which are located at the leading side and trailing side and which support the lining carrier plate 41. The lining horn-like members 3 and 4 and the bridge portion 7 which connects them form the lining shaft in which the brake lining is guided with play (see gap 42).
In order to assemble or disassemble the lining carrier plate 41, it is inserted perpendicularly into the gap between the two lining horn-like members 3, 4, wherein the lining horn-like members 3, 4 extend as far as the radially external edge or practically as far as the edge of the brake lining carrier plate 41. In this case, both the inner faces 5, 6 of the lining horn-like members 3, 4 and the adjacent support faces 46 of the lining carrier plate 41 are constructed as planar faces. In this case, the rear carrier horn-like member in a main rotation direction MRD of the brake disc, that is to say, the rotation direction of the brake disc during forward travel of the motor vehicle, is referred to as the leading-side carrier horn-like member 3. It is further possible to see a gap 42 between the leading-side support face 46 of the lining carrier plate 41 and the leading-side lining horn-like member 3, as a result of which the play and the above-described impact noises are produced. In order to prevent such effects, various solutions are known according to the prior art.
U.S. Pat. No. 3,885,651 discloses the arrangement of a separate lining shaft spring between the brake lining and the carrier. A disadvantage therein is that the lining shaft spring is compressed during a braking operation in the reverse direction in such a manner that a plastic deformation cannot be excluded. In this case, a subsequent correct function of the lining shaft spring would no longer be ensured.
However, the Published German Patent Application DE 10 2012 002 734 A1 proposes the arrangement of a resilient element on the base of the lining shaft, which resilient element presses the brake lining radially against round guide faces. The construction proposed in DE 10 2012 002 734 A1 cannot be implemented with standard lining shafts and prevents normal insertion of the brake linings in a radial direction. In order to change the linings, they first have to be moved after complete resetting of the pressure pieces in the direction towards the brake disc until they have completely left the lining shaft in this direction. Only then is it possible to remove them in a radial direction. However, this means a greater operating complexity, particularly if the brake linings are intended only to be inspected but not changed.